public void WristPointingUp()
                {
                    Vector3 elbowToWrist = new Vector3(0, 1, 0);
                    double  angle        = InverseKinematics.GetElbowAngle(shoulderToElbow, elbowToWrist);

                    Assert.AreEqual(-90, angle, angleTolerance);
                }
                public void Inline()
                {
                    Vector3 elbowToWrist = new Vector3(-1, 0, 0);
                    double  angle        = InverseKinematics.GetElbowAngle(shoulderToElbow, elbowToWrist);

                    Assert.AreEqual(0, angle, angleTolerance);
                }